'''
Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a list of favorite restaurants represented by strings.

You need to help them find out their common interest with the least list index sum. If there is a choice tie between answers, output all of them with no order requirement. You could assume there always exists an answer.

Example 1:

Input:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["Piatti", "The Grill at Torrey Pines", "Hungry Hunter Steakhouse", "Shogun"]
Output: ["Shogun"]
Explanation: The only restaurant they both like is "Shogun".

Example 2:

Input:
["Shogun", "Tapioca Express", "Burger King", "KFC"]
["KFC", "Shogun", "Burger King"]
Output: ["Shogun"]
Explanation: The restaurant they both like and have the least index sum is "Shogun" with index sum 1 (0+1).

Note:

    The length of both lists will be in the range of [1, 1000].
    The length of strings in both lists will be in the range of [1, 30].
    The index is starting from 0 to the list length minus 1.
    No duplicates in both lists.
'''

class Solution(object):
    def findRestaurant(self, list1, list2):
        """
        :type list1: List[str]
        :type list2: List[str]
        :rtype: List[str]
        """
        map1 = {list1[i]: i for i in range(len(list1))}
        map2 = {list2[i]: i for i in range(len(list2))}

        inter = set(list1) & set(list2)
        sum_index = {i:map1[i] + map2[i] for i in inter}
        return [val for val in inter if sum_index[val] == min(sum_index.values())]


